1. Field of the Invention
The present invention is related to a luminescence lamp, and more particularly, to a flat luminescence lamp and a method for fabricating the same.
2. Background of the Related Art
Extra slim flat panel display devices that have a thickness less than a few centimeters have diverse areas of application, such as liquid crystal displays (LCDs) for notebook computers, monitors, spacecraft, and airplanes. Of the many different types of LCDs, the passive luminescence type LCD includes a backlight to be used as a light source disposed at the rear of a LCD panel. However, the use of such backlights in LCDs is inefficient in view of their weight, power consumption, and thickness.
Backlights that are commonly used in LCD devices are generally cylindrical fluorescent lamps disposed beneath a LCD panel. However, the fluorescent lamp must be spaced from the LCD panel in order to prevent the fluorescent lamp from being seen on the LCD panel. Accordingly, a light scattering mechanism is required to provide a uniform distribution of light across an entire surface of the LCD panel. Moreover, the specific type of fluorescent lamp disposed beneath the LCD panel limits the fabrication process of making a thin LCD panel. When a large-sized fluorescent lamp size is disposed beneath the LCD, a larger area of the light emitting surface is required.
In a LCD device using a fluorescent lamp fitted with a light plate, the fluorescent lamp is disposed to an outer circumference of the LCD panel for scattering light to an entire surface of the LCD panel. By using the light plate, a total luminance of the fluorescent lamp is low since the light must transmit through the light plate. Moreover, to ensure uniform distribution of the light upon the LCD panel, a high degree of optical design and fabrication technologies are required. Currently, a fluorescent lamp disposed beneath the LCD is suggested in which a number of individual lamps, or a single lamp that has multiple bends, are disposed beneath a display surface of the LCD panel.
A typical flat luminescence lamp will be explained with reference to FIGS. 1 and 2. FIG. 1 shows a plan view of a flat luminescence lamp according to the related art, and FIG. 2 shows a cross-sectional view across line I—I′ of FIG. 1.
In FIG. 1, a luminescence lamp of the related art is provided with a lower plate 11 and an upper plate 11a, a cathode electrode 13 disposed upon the lower plate 11, an anode electrode 13a disposed upon the upper plate 11a, a rectangular frame that includes four frame portions 19a, 19b, 19c, and 19d sealing the upper plate 11a and the lower plate 11 by solder means, such as glass solder, and a plurality of supporting bars 21 disposed between the lower plate 11 and the upper plate 11a. 
The anode electrode 13a includes multiple portions that are arranged at fixed intervals in pairs of two, and the cathode electrode 13 includes single portions that are arranged at fixed intervals upon the lower plate 11 facing opposite to a space of the upper plate between the anode electrode 13a. The cathode electrode 13 and the anode electrode 13a are covered with dielectric material, and each has lead lines electrically connected thereto for applying external voltages. The upper plate 11a and the lower plate 11 each have surfaces covered with fluorescent material and are disposed to opposite to each other with a discharge space formed therebetween. The discharge space includes xenon Xe gas that forms a plasma to emit UV rays when the external voltages are applied to the cathode electrode 13 and the anode electrode 13a. The UV rays collide with the fluorescent material disposed upon both the upper plate 11a and the lower plate 11, and excite the fluorescent material to generate visible light. Additionally, a reflective plate 14 is disposed above the cathode electrode 13 to prevent any light generated within the discharge space from leaking toward a back surface of the lower plate 11. Accordingly, the supporting bars 21 are formed of glass for transmitting the light.
In FIG. 2, the lower plate 11, which is made of glass, includes the cathode electrode 13 and a dielectric material layer 12 formed to cover the cathode electrode 13. The reflective plate 14 is disposed upon the first dielectric material layer 12, and a first fluorescent layer 15 is disposed upon the reflective plate 14. The anode electrode 13a is disposed upon the upper plate 11a, which is also made of glass, for inducing a discharge in association with the cathode electrode 13. A second dielectric material layer 12a is disposed upon the upper plate 11a to cover the anode electrodes 13a, and a second fluorescent material layer 15a is disposed upon the second dielectric material layer 12a. The frame portions 19a, 19b, 19c, and 19d are all formed between the upper plate 11a and the lower plate 11 for sealing the upper plate 11a and the lower plate 11 by glass solder. A flat heat dissipation plate 23 is disposed upon a back surface of the lower plate 11 for dissipating heat that is generated during discharge to an exterior of the lamp. The cathode electrode 13 and the anode electrode 13a are formed by either a silk print process or a vapor deposition process. Upon the application of the external voltage to the cathode electrode 13 and the anode electrode 13a via the lead lines, the xenon Xe gas within the discharge space disposed between the cathode electrodes 13 and the anode electrodes 13a forms a plasma. Accordingly, the plasma emits UV rays that collide with the first fluorescent material layer 15 and the second fluorescent material layers 15a to generate visible light, thereby illuminating the flat luminescence lamp.
However, implementing the flat luminescence lamp as described in a lightweight display, such as a notebook PC, increases thickness and weight since it uses two glass plates for the upper lower plates as well as a heat dissipation plate on the back surface of the lower plate.